1. Field of the Invention
This invention relates in general to certain new and useful improvements in stringed musical instruments and, more particularly, to stringed musical instruments of the type having an elongate neck and a body and which are capable of generating sounds in response to vibration of strings extending across that body and with fingerboards substitutable for one another on the neck of that instrument.
2. Brief Description of the Related Art
In stringed musical instruments the useful or active length of the string is adjusted by pressing the string against a fingerboard on the upper surface of the neck. In generally all cases, the fingerboard is an integral part of the neck of the musical instrument, or otherwise it is permanently affixed to the neck. However, some musical instruments are provided with frets on the fingerboard and are typically referred to as "fretted" musical instruments which allows the user to engage the string of the instrument against a fret so that a useful length is achieved equal to the distance between the fret and the bridge. This will create a note of precisely defined timber and also of metallic character. Other instruments without frets are often referred to as "fretless" instruments and the useful length of the string is determined by the distance between the point at which the player keeps the string pressed against the fingerboard and the bridge. In absence of the fret, there is a lack of metallic quality to the sound and the sound also has a softer character.
It is, however, important in connection with any stringed musical instrument to insure that the distance between the string in its normal unactuated condition and the upper surface of the fingerboard is precisely controlled and remains the same. Otherwise, if this distance should effectively change, even by a small amount, the musical quality of the instrument is altered and frequently to the detriment of the generated sounds. Moreover, it is critical in connection with any stringed musical instrument to insure that the fingerboard is tightly mounted onto the neck of the musical instrument. Otherwise, vibrations between the fingerboard and the neck of the instrument would be generated and this, again, results in a deficit of the musical quality.
It may be appreciated that for certain musical pieces, fretted instruments are desired and for other musical pieces, fretless instruments are desired. However, since there is no convenient means for altering an instrument with frets, or without frets, the average musician must constantly carry at least two such instruments, one containing frets and one without frets. In particular, for the bass guitar and the slide or so-called "bottle neck" six-string guitar, each player almost inevitably carries at least two musical instruments for this purpose. However, this limits the player in attaining the desired musical flexibility while retaining the feel and capabilities of a preferred instrument.
There have been at least two proposals to provide a stringed musical instrument with interchangeable fingerboards. One such proposed arrangement is set forth in U.S. Pat. No. 4,137,813, dated Feb. 6, 1979, to Stone, et al. In this patent, Stone, et al proposed interchangeable fingerboards having differed fret arrangements, but never suggested the concept of substituting a fretted board for a non-fretted board. Stone, et al did suggest the mounting of a fingerboard to a musical instrument in a detachable fashion, but pointed out the critical problem of potential vibration which can result between the neck of the instrument and the fingerboard. The Stone, et al '813 patent, however, proposed groove arrangements in both the underside of the fingerboard and the upper surface of the instrument neck.
In U.S. Pat. No. 4,132,143, dated Jan. 2, 1979, to Stone, the patentee employs a plurality of very closely spaced apart grooves on the underside of the fingerboard and projections on the upper surface of the neck. These grooves and projections are longitudinally spaced apart from one another by very short distances and, hence, a large number of such grooves and projections are employed. Although Stone may potentially eliminate the problems of vibration, this arrangement also creates a rigidity and does not allow the fingerboard to conform to the arc of the neck accounting for the normal flexing of the neck and makes insertion of the fingerboard virtually impossible. Consequently, the arrangements in the Stone, et al '813 and in the Stone '143 patent have not been effectively commercially utilized.
U.S. Pat. No. 4,852,450, to Novack, also discloses different fret arrangements for use on musical instruments. However, the fingerboards containing these different fret patterns are not removably mounted on the neck of the musical instrument, as such.
There have been several attempts in the prior art to provide stringed musical instruments in which frets can be used or withdrawn. In U.S. Pat. No. 4,267,936 to Mouton, there is provided a stringed musical instrument having retractable frets. In this case, an electric base guitar is provided with retractable frets, such that in one position, the frets are flush with the surface of the fingerboard and, in another position, the frets are raised above the surface of the fingerboard. The neck of the instrument has an inclined slope on one side causing wedge shaped feet on the frets to ride on this inclined slope for raising and lowering the frets.
There is a also a proposed stringed musical instrument having retractable frets described in U.S. Pat. No. 4,772,260 to Pigozzi. In this case, a guitar has a fingerboard in which the frets are slidably disposed within the neck holding the fingerboard. A rather complex mechanism, including cams, springs and a rotatable shaft, are provided for raising and lowering the frets. While this type of instrument may be attractive in theory, as a matter of practicality, the mechanism used is quite complex and significantly adds to the overall weight, and certainly to the cost of the musical instrument.
In each of the aforesaid prior art systems for providing frets and effectively removing frets, they would be inherently slow and cumbersome. Consequently, these systems are not effective for the average musician who desires to quickly change from a fretted instrument to a fretless instrument. As a result, systems of the types proposed in these patents have not been effectively used.
There has clearly been a need for a single musical instrument which can be properly tuned and adapted to the particular use of a certain musician. Clearly, the complex and unworkable proposals advanced in Pigozzi patent and in the aforesaid patent to Mouton have not been effective and not usable in terms of converting a single musical instrument from a fretted instrument to a non-fretted instrument. Moreover, and although the aforesaid Stone patents suggested the changing of fingerboards, Stone never suggested the alteration of the same musical instrument from a non-fretted to a fretted instrument. In addition, the interlocking arrangement of the fingerboard to the neck of the musical instrument was literally unusable in actual operation due to the complexity and difficulty of changing one fingerboard for another. Thus, this need has existed and still remains.